Artificial limb



J. F. ROWLEY.

ARTIFLClAL LIMB.

APPLICAT ON FILED JULY 6,1920.

1,375,860, Patented Apr. 26, 1921.

Q EF W a,

. UNITED STATES PATENT OFFICE.

JAMES F. ROWLEY, OF CHICAGO, ILLINOIS.

ARTIFICIAL LIMB.

' cifically to means for varying the degree of opposed flexing and straightening actions in a jointed limb. For instance, in walking it is desired that an artificial leg simulate perfectly the cycle of actions occurring in the natural leg, that is, as the body swings forward around the foot as a pivot the leg reinains substantially straight, flexing slightly as the'opposite foot approaches the ground. The bend in the knee increases, as the weight is transferred to the opposite leg and the foot leaves the ground, raising the foot high enough to clear ordinary irregularities of the surface of the ground, and gradually straightens as the leg moves toward the extreme forward position.

7 The purpose of the invention is to provide for effectingthe above-mentioned action by interacting means for first flexing the leg and then straightening it during its forward swinging motion. These combined devices are designed 'to act as required for normal walking without any particular efiort on the part of the wearer of the limb and to be under his control for increased action b the natural relaxation or extension of t e upper part of his body or shoulders.

A further purpose of the invention is to provide means for reducing or minimizing the effectiveness of the leg straightening appliance during ordinary walkin The natural extension of the body or a s oulder.

action without appreciable eifort supplies more power than is necessary for straightening the leg. It is therefore practicable and advantageous to provide means for reducing the maximum effective leverage posslble with the space available, this reduction being in effect only when the leg is in substantially a straightened position.

The objects of the invention are accomplished by the structure shown in the accompanying drawings in which-- Figure 1 is a sectional view showing the Specification of Letters Patent.

Patented Apr. 2c, 1921.

1920. Serial N0. 394,062.

knee-joint of an artificial leg provements applied thereto. Flg. 2 1s a plan view of the knee-bolt and connecting mechanism.

Fig. 3 is a perspective view clal limb and its suspender. v

The invention may be carried out in any customary construction of artificial leg wherein provision is made for straightening the leg on a forward motion. Such a de vice is illustrated in applicants Patent No. 961,165, June 14;, 1910. The embodiment of the invention as illustrated comprises upper and lower le -sections having a jointed connection including a lever attached to the lower leg-section and fulcrum at such jointed connection. extends forwardly of the pivotal connection, and slidably connected to the free end of the lever are the loops of the usual suspender. The Suspender passes over the shoulders of the wearer andby an upward extension of his body, or one or both shoulders, the 'suspender is tensioned and draws upwardly on the forward end of the lever,

of the artifiwith the im- The'free end of the lever thus swinging the lower leg-section toward straightened relation with the upper legsection.

Resilient means are opposed to the leg straightening mechanism for the purpose of .flexlng or bending the leg when it is lifted from the ground.

Referring to the drawings,'the upper and lower sections 1 and 2 respectively, are piv oted together by the usual knee-bolt 3. The lever 4, centrally located on the knee-bolt and mainly within the upper leg-section, has the lower end ofits arm 5 attached to the lower leg-section 2 and the upper arm 6 of the lever is forked tocarry pulleys 7 around which the suspender loops 8 pass. These loops also pass around pulleys 9 located at the rear of the bolt 3 and held in spaced relation with the pulleys 7 by links 10 which are free to oscillate around the supporting pin 11 of pulleys 7. Attached to the links 10 by the U-shaped clip 12 is a resilient web 13. This web passes downwardly over the rear surface of the lower leg-section 2 and at its lower end is attached thereto by the fastening 14. The clip 12 is attached to the links 10 at one of the apertures 14. By this arrangement the extensible elastic web 13 opposes an upward rocking motion of links 10 as occurs when drawing upwardly on the suspender loops 8. If the leg is lifted and relieved of weight thereon and the suspend ers are not under much tension, the elastic web bends the knee-joint. By drawing upwardly on the suspenders the wearer is enabled to overcome the action of the elastic web 13 to any desired extent.

Another phase of the invention enabling a user of the device to more satisfactorily control the action of the leg, is the fact that the suspender loops pass around both the pulleys 7 and 9 which are respectivelsy at the front and rear of the knee-bolt 3. ince the pulleys 9 are carried by links which may swing around the center of the pulleys 7, the maximum effective leverage which the suspender has on the lower leg-section is represented by the length of the arm 6 of lever 4. With this leverage not much effort is required on the part of the wearer of the limb to straighten the lower leg in respect to the upper leg section. In fact the structure is somewhat too sensitive in this respect under normal walking conditions without the opposition of the elastic web 13. This web therefore improves the action of the device by resisting a too rapid forward swing ing of the lower leg section due to pendulum action or a slight tensioning of the suspenders. The tension of the web 13 measured with respect to the ull the user can effect through the suspen ers, is a comparatively small amount. Therefore at such times as he desires to obtain the full benefit of the leverage possible with the lever 4, the tensioning of the suspender results in swinging the links 10 to the dotted line position shown in Fig. 1, so that after the resistance of web 13 is overcome, additional tensioning of the suspender results in the most direct pull on the upper arm 6 of the lever 4.

In the operation of the device the act of walking results in the wearer transferring his wei lit from one leg to the other, thus regularIy relieving the artificial leg of its loadand permitting elastic web 13 to flex the leg. As the thigh, upon which the artificial leg is fitted, swings forwardly, the suspenders are tensioned without appreciable shoulder action, thus operating against the web 13 by drawing upwardlv on the forward end of the lever 4. The lower leg-section is thus gradually brought toward a straightened position as the leg swings forward. The weight of the lower leg in swinging forward also acts in opposition to web 13.

Although but one specific embodiment of this invention has been herein shown and described, it will be understood that numerous details of the construction shown may be altered oromitted without departing from the spirit of this invention as defined by the following claims.

I claim:

1. In an artificial leg upper and lower leg-sections pivoted together, means operable by an extension of the body of the wearer for swinging the lower leg-section toward straightened position with respect to the other leg-section, and a resilient leg flexing means opposed to the straightening action.

2. In an artificial leg composed of upper and lower leg-sections pivoted together, a resilient means for increasing the angular relation between the two leg-sections, and means for moving the leg-sections toward straightened relation with each other upon a forward motion of the leg in walking.

3. In an artificial leg composed of upper and lower leg-sections pivoted together, a resilient means for increasing the angular relation between the two leg-sections, means operable by an extension of the body of the wearer for swingin toward straightene position with respect to the other leg-section, a resilient means opposed to the straightening action. I

4. The combination of a thigh-section and a leg-section connected by a knee-joint, a suspender slidingl connected to said thighsection to have a sliifting movement relative thereto adapted to ass over and be suported on the shoulder of the wearer and aving a flexible extension running to the inside of the thigh-section, and intermediate means connecting said extension with said leg-section and adapted to move the leg-section on its knee-joint through tension of said suspender, and a resilient leg-flexing means acting on the lower leg-section in opposition to the action of said suspender.

5. The combination of a thigh-section and a leg-section connected by a knee-joint, with a suspender connected to the leg-section at a point providing leverage outside of the arms of t e knee-joint, sald suspender having a shifting movement relatively to said oint and adapted to extend over the shouler of the wearer to form a shoulder strap, said suspender having a part, betweensaid point and said shoulder strap extending through the interior of the thigh-section, and a resilient leg flexing means opposed to the action of said suspender. I i

6. The combination of a thi h-section, a leg-section pivotall connecte thereto, a suspender operative y connected to the outside of said thigh-section and having a flexible extension running to the interior of said thigh-section through holes in the walls thereof, and rigid connecti means between said extension and sai leg-section, and a resilient leg flexing means 0 the lower leg section in opposition to the action of said suspender.

7. An artificial limb comprising jointed sections, and means for changing the angular relation of said sections said means including a lever and a resilient element for the lower leg-section rable on reducing the effectiveness of. said lever until said means is operated to a predetermined extent.

8. An artificial limb comprising jointed sections, and means for changing the angular relation of said sections, said means including a lever and an element for reducing the effectiveness of said lever until said means is operated to a predetermined extent.

9. An artificial limb comprising jointed sections, and means for changing the angular relation of said sections, and a movable element for increasing the effectiveness of said means during its operation.

10. An artificial limb comprising jointed sections, a lever secured to one section and having a fulcrum connection with the remaining section, a link pivoted to said lever, a pair of bearings s aced by said link, a suspender coacting Wit both of said bearings, and resilient means for restraining pivotal motion of said link under the action of the suspenden 11. An artificial limb comprising jointed sections, means for changing the angular relation of said sections, includin a lever and a movable element for changing the effectiveness of said lever during action of said means.

Signed at Chicago this third day of July, 1920.

JAMES F. ROWLEY. 

